1. Field of the Invention
The present invention relates generally to a disc drive system and more specifically to a disc drive system which has a disc loading/ejection control mechanism.
2. Description of the Prior Art
FIGS. 3A and 3B show a conventional floppy disc drive control system as an example of a disc drive system of this type. It will be noted that FIG. 3A illustrates the condition that a disk is loaded and clamped, while FIG. 3B shows the condition that the disk loaded is ejected from the drive.
In FIGS. 3A and 3B, reference numeral 1 denotes a main body of the disc drive. Reference numeral 2 denotes a known drive controller for controlling the loading and ejection of a floppy disc 11. Reference numeral 3 denotes a read/write head for writing or reading data into or from the floppy disc 11. Reference numeral 4 denotes a stepping motor for displacing the read/write head 3 radially forward and backward in the direction intersecting concentric tracks on the floppy disk 11. Reference numeral 5 denotes a spindle motor for rotating the floppy disk 11. Reference numeral 6 denotes a track 00 sensor for detecting the track 00 on the floppy disk from the position of the head 3; 7, a media-in switch for detecting the insertion/ejection of; and 8, a clamp-end switch for detecting the loading position of the floppy disk 11. In FIG. 3A, the switch 8 detects the loading position of the floppy disk 11. In FIG. 3B, the switch 8 detects that the floppy disk 11 is not at the loading position. Reference numeral 9 denotes an eject-end switch for detecting that the floppy disk 11 is ejected. In FIG. 3A, the switch 9 detects that the floppy disk 11 is not ejected. In FIG. 3B, the switch 9 detects the ejection of the floppy disk 11. Reference numeral 10 denotes an eject switch for instructing the drive controller 2 the start of an ejection operation. Reference numeral 12 denotes a clamp arm for clamping the floppy disk 11.
Reference numeral 13 denotes a clamp arm driving roller 13 which is disposed in engagement with the upper surface of the clamp arm 12 and arranged to drive the clamp arm 12 vertically. Reference numeral 14 denotes a roller disposed in contact with a cam 16 so as to be driven by the cam 16 and for driving a disc ejection lever 15 via a known mechanism by transmitting the force by the cam 16 as a disc loading/ejection drive force. The disc ejection lever 15 transmits the loading/ejection drive force to the roller 13 and also controls the ON/OFF switching of the clamp end switch 8 and the eject end switch 9.
The cam 16 is driven by a clamp/eject motor 17. In FIGS. 3A and 3B, arrows 18 and 19 respectively indicate forward and reverse rotational directions of the cam 16. When the cam 16 is rotated forward, the disk 11 is clamped. When the cam 16 is rotated reversely, the clamp is released and the disc 11 is ejected.
FIG. 4 is a timing chart illustrating one example of the operation of the disc loading/ejection control system shown in FIGS. 3A and 3B. In FIG. 4, "a" denotes a waiting or transient time of the switches 7-10. In other words, the switch outputs are stably obtained after the waiting time "a". "S", "F" and "R" denote the stop, the forward rotation and the reverse rotation of the motor 17, respectively. At instant To, the disk 11 is in an eject condition shown in FIG. 3B. At instant T1, the floppy disc 11 is inserted and the media-in switch 7 is switched to an ON state so that the disc loading operation is started. Instants T1, T5, T6 and T7 denote the change of the rotation of the cam 16 during the normal loading/ejection operation.
At instant T1, the cam 16 is rotated forward in the direction indicated by the arrow 18 to drive the roller 14, the lever 15 and the roller 13 so as to clamp the disc 11, thereby performing the disc loading. As a result, the eject end switch 9 is rendered from an ON state to an OFF state. At the instant T5, the clamp end switch 8 is rendered to an ON state and the cam 16 is stopped. As a result, the disc loading operation is completed, as shown in FIG. 3A.
Subsequently, at the instant T6, the eject switch 10 is rendered to an ON state and the eject motor 17 is rotated reversely, thereby performing operations in reverse of operations at the time of the disc loading. At instant T7, the eject end switch 9 is rendered to an ON state and the ejection operation is completed, as shown in FIG. 3B.
An operation at instants To', T1', T2, T3 and T4 shows that the floppy disc 11 is removed during the disc loading procedure.
At instant To', like instant To', the floppy disc 11 has been ejected. At instant T1', like instant T1, the floppy disc 11 is inserted. Then, the media-in switch 7 is rendered to an ON state and the disc loading operation is initiated. Subsequently, at instant T2, the floppy disc 11 is removed. Then, the media-in switch 7 is rendered to an OFF state. It will also be noted that at instant T2 the eject end switch 9 is interrupted.
Further, at this instant T2, the clamp/eject motor 17 is stopped, so that the forward rotation of the cam 16 in the direction indicated by arrow 18 is stopped. Following the expiration of a time duration defined between instants T2 and T3, the motor 17 rotates in the reverse direction at instant T3 to rotate the cam 16 backward. At instant T4, the eject end switch 9 is rendered to an ON state and the motor 17 stops. Accordingly, the cam 16 also stops, as shown in FIG. 3B.
However, with the above-described conventional arrangement, it is necessary to provide both the clamp end switch 8 and the eject end switch 9 as means for detecting both the clamp and ejection of the floppy disc. Accordingly, this arrangement of course increases the total number of switches required and thus increases the number of parts and assembly works and the total cost of the system.